Forest suberin fatty acids enable tailored and layered multifunctional electrospun polycaprolactone-chitosan nanofibers

Current electrospun tissue engineering scaffolds still face challenges in simultaneously achieving adequate mechanical stability, tailored surface functionality, and multifunctional performance. To address this limitation, this study aimed to develop multifunctional biodegradable nanofibrous scaffolds using forest-derived suberin fatty acids (SFAs), selected as renewable functional additives because of their amphiphilic chemical structure and their potential to tailor both bulk and surface properties. Electrospun polycaprolactone/chitosan (PCL/CS) nanofibers were functionalized with SFA either by incorporation into the polymer matrix or by surface application through coating. The resulting nanocomposites were characterized in terms of their structural, thermal, mechanical, and biological properties by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), swelling and degradation analyses, tensile testing, antibacterial assays, and fibroblast viability studies. SEM analysis revealed that incorporating SFA into the PCL/CS matrix significantly reduced fiber diameter and narrowed the fiber diameter distribution. In contrast, coating the surface with SFA modified the fiber topography and surface compactness. Matrix incorporation of SFA enhanced early-stage water uptake and degradation, whereas surface coating resulted in a more gradual hydration response. Notably, the dual-loading system (PCL/CS/SFA + SFA coated) minimized both swelling and cumulative degradation, indicating enhanced barrier performance. Mechanical testing showed that matrix incorporation enhanced tensile strength while surface coating preserved ductility. Numerical analyses further revealed that SFA incorporation increased the critical buckling load and stress values, whereas SFA coating led to a decrease in these properties. Antibacterial assays demonstrated strong inhibition against Staphylococcus aureus (≈ 93%) with no effect on Escherichia coli . Biocompatibility studies confirmed excellent fibroblast compatibility for all SFA-modified nanofibers, while matrix incorporation of SFA favored early-stage cell proliferation. Overall, the proposed dual-functionalized PCL/CS/SFA nanofibrous system represents a sustainable strategy for tailoring both bulk and surface properties, highlighting its potential for wound dressing and other temporary biomedical applications.